In a back end process (BEOL: Back End Of the Line) of a semiconductor manufacturing process, an etching method is also used, so that various kinds of etchant are developed. Typically, etchant dissolves metal, so that etchant containing metal is disposed of as waste liquid.
Expensive etchant has been developed in many cases, so that it is desirable to reclaim such etchant by removing dissolved metal by using a method of some sort. For this reason, various techniques for removing and recovering metal dissolved in etchant have been conventionally studied, and Patent Document 1 provides a technique for capturing metal dissolved in etchant by using a carrier with a chelation group to reclaim the etchant, for example.